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2016 Mercedes-Benz E-Class has a loud startup rattle

I bought a used 2016 MB E350 Sedan. When I start it up and the motor is cold the motor makes a rattling noise that is louder than the radio. It drives me crazy. The MB dealer told me that is normal in the 2015 thru 2019 MB E350’s. Can you recommend how I can make the noise less noisy. I have had 7 MB’s before this one and they were all very quiet.
Thanks in advance for you help.

Me thinks the dealer is not being honest. Did you purchased it “as is, no warranty “.

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It’s entirely possible that the oil filter is not of the correct specification, and it is even possible that the oil is not the correct viscosity. Start off with an oil and filter change at an independent foreign-specialist mechanic’s shop where they know their way around Benzes. With any luck, the noise will cease after that oil and filter change.

It would help to ask dealer to test-drive another MB with the same kind of engine, where you will be tho one starting it from cold on the parking lot.

Some cars now shift valve-train and ignotion from the start to promote a fast warmup cycle, and it sounds like a rattling until car warms up in a minute or so. I know of Mazda and Subaru as two who does that, probably some other makers do it too, so I would not discount a possibility that MB is doing the same.

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I would make sure an OEM filter is installed with a proper anti-drainback valve. I would also make sure the oil is of the correct viscosity and rating for this car. Remember that European cars specify certain oils so not just any will do. My parents drive Mercedes Benz as well. The cheapest oil I have found that meets spec is a Mobil 1 0W40 European that you can get for like $22/5 quarts at Wal-Mart. Their car takes 9 quarts so you might or might not need TWO of these. I suggest making sure the correct oil and filter have been used, then test drive another similar car as others have suggested.

The rattling sound could be coming from other parts of the car too, like the ABS system, the HVAC system, or even the evap system. On newer cars the ABS system is sometimes tested each time during start-up and that can make a sort of rattling-like noise. HVAC vent door actuators can lose their home position, and them re-homing can make weird noises. And there may be an evap system air pump on your car which could make similar noises in normal operation. The idea above to check other cars on the MB lot for comparison is a good one. May just be normal for that car.

Purebred

    December 11

Me thinks the dealer is not being honest. Did you purchased it “as is, no warrant”?

The factory warranty applies, regardless.

If a Benz dealership finds an oil filter of the wrong specification, they could void the factory warranty on the engine.

I agree. I was responding to the questions about the ‘as is, no warranty’. That doesn’t eliminate the factory warranty.

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well, maybe it is a cold engine rattle and was not noticed during the test drive as car was warm?
you do not say if it rattles when car is restarted/warm

I purchased a used 2016 MB E 350 Sedan in July 2018. A couple of months ago I kept hearing the engine making a noise like a rattling noise. It is real loud when the engine is cold and then gets a little quieter when the engine warms up. The MB dealer who I took it to told me that it is normal in MB’s from 2015 to 2019. I find it hard to believe. It is louder than the radio. Put, put, put, put,put put just like an old car. do you know anyway this can be made quieter. It drives me crazy. I had a 2013 MB E 350 and it was real quiet as were all of my other 5 Mercedes.

Have you tried any of the above suggestions?

I doubt the oil filter will make any difference, it is just an insert, no “valves”.

On late model vehicles owners complain about the sounds from the air injection system, the high pressure fuel pumps, the injectors, the timing chain, etc. The sounds usually aren’t terribly disturbing but they make some people worry.

That is true. The fact the filter is just an insert kinda omits the filter from the equation.

I am not familiar with this engine but the timing chain is a good suggestion. Many have a hydraulic tensioner so maybe this is bleeding down after it sits of a while and the chain rattles before it can build pressure.